Causes of Acne

I am one of those who are blessed with acne-free skin. Even during my teen years where I had drastic hormonal change, I did not experience having acne or even pimple. Looks like it is in our genes as all of us have this acne-free skin except for my brother who used to have acne. He started to have little pimples when he was on his early teens that turned into acne when he was already in college. Now, his acnes are gone after using some acne products but there were lesions left on his skin.

Acnes are sign of adolescence. But why is it not fair? Most teens get acne at some point while some are not? Well, according to researchers, there are three main reasons for acne; the hormones, the diet and stress. What do you think caused yours?